Modifiers
Modifiers are changes a guest makes to a menu item, such as less spice, no onion or oat milk, recorded with the item so the kitchen prepares it right.
Almost every busy service has them. A guest wants a latte with oat milk, a curry less spicy, or fries without salt. If the change is lost between the guest and the kitchen, the dish is remade and the guest waits.
POS systems handle modifiers in two ways. Some use modifier groups: fixed choices such as size or milk type, often with a price, that staff tap from a list. Others use a free-text note on each item, which the kitchen reads on the ticket or screen. Groups are faster and can change the price; a note is simpler and covers any request.
Either way, the modifier should travel with the item to the kitchen display and the printed ticket, so the cook sees it before starting the dish.
Example
A guest at a dal bhat restaurant in Kathmandu asks for the tarkari with no chilli. The waiter types it as a note on that item, and the cook sees it on the kitchen screen next to the dish.
KalasOS specifics
KalasOS uses a free-text note on each item: "Special requests / modifiers" on the waiter screen and "Special requests" on the kiosk and cashier screens. The note shows on the kitchen display and the printed KOT. There are no priced modifier groups, so a change that costs extra needs its own menu item, or a custom item with a price.